Antenna construction



May 23, 1944. E. CARLSON ANTENNA CONSTRUCTION Filed June 22, 1940 INVENTOIQ W w FIG.2

EMIL CA BY X'- FIG.5

Patented May 23, 1944 ANTENNA CONSTRUCTION Emil Carlson, Detroit, Mich assignor to Pioneer Specialty CompanyyDetroit, Mich., a corporationof Michigan Application June 22, 1940,: Serial No. 341,953

This invention relates to'radio antennae, and particularly to improved remotely operable, telescopically extensible and retractible antennae of the relatively rigid, self-supporting type.

The invention contem plates. the provision of.

improved means for extending and retracting such a telescoping" antenna, which means is of extremely simple and positive mechanical character, operable by means of a crank or knob from a remote point. A related object is to provide improved means utilizing a simple stiff wire' to extend and retract a telescoping antenna of the character indicated, which wire is adapted to be wound upon and unwound from a drum as the knob or crank is turned to retract or extend the aerial. While attempts to create a practical device of this character have been made in the past, it is believed that equivalent results have not heretoforebe'en secured, with a device of comparably simple, inexpensive and reliable nature,

while these characteristicsare required to a high degree to render feasible the installation of such aerials upon passenger automobiles.

a preferred embodiment of -my invention and wherein similar reference numerals designate similar parts throughout the several views.

Inthe drawing:

.F a. 'fis ra men air a d mew t d grammatic side elevational View of a motor vehicle equipped with an improved antenna system constructed and installed in accordance with the present invention.

Fig. 2 is a view partly in side elevation and partly in substantially central vertical section, showing the aerial construction removed from the vehicle.

Fig. 3 is a cross section taken substantially on the line 3--3 of Fig. 2 and looking in the direction of the arrows.

Fig. 4 is a sectional view taken substantially on the line 4-4 of Fig. 2 and looking in the direction of the arrows; and

Fig. 5 is an enlarged detail section of the friction imposing and electrical connecting means by which the telescoping sections are interconnected.

Referring now to the drawing: reference charactor I DA designates generally. the body of a closed motor vehicle. The passenger compartment is formed by a raised section IZA of the body, and a cowl portion llA adjacent the same, the entire body being sheathed in sheet metal.

The aerial proper consists of three telescoping metallic sections 2 IA, 22A, 23A, the first of which, comprising the outer section, is fixedly attached at its lower end to a supporting casing I00 formed of insulating materialQs'uch as hard rubher, this assembly being, in the installation shown, attached to the cowl 1 IA with the antenna sections projecting thereabove and the casing arranged therebelow in a manner presently to be described in greater detail. A generally cylindrical opening extends inwardly iroin one face of the casing, adapted to receive a conformably shaped. reel, I02, rotatably mounted therein and also formed of insulating material. In the shown construction the reel is rotatably attached to the casing by means of a flanged metallic hub I04 carried by and rotatable upon a post [05 secured in the casing at the axis of the cylinder opening, as by means of the screw 101. The reel is adapted to be turned from a remote point, as by means of a Bowden wire assembly I08 attached to the hub I04.

The cylindrical opening in the casing into which the reel is fitted is of stepped counterbored form, as best shown in Fig. 3, the stepped contour being provided by an annular reentrant shoulder, H0, formed at the bottom outside'corner of the reel opening. The reel is contoured to conform closely to and fill the entire reel opening, fitting snugly against both sides of the reentrant shoulder H0.

A cylindrical slot. H2 extends inwardly of the reel from a point substantially in line with the inner edge ofthe shoulder I Ill. The slot is wide enough, in its radial dimension, to receive only a single turn of the wire, I [5, which is used to actuate the telescoping aerial sections, but is deep enough to receive several turns along its length. The wire is thus prevented from piling up; that is, it can be wound into the slot helically, but one turn cannot overlie another. Stiff piano wire or the like is attached to the innermost section 23A of the telescoping aerial assembly, and projects downwardly through a restricted opening H6 which opens into the interior of the casing at a point lying substantially at the juncture of the slot H2 with the shoulder H0, and tangentially with respect to the reel. The restricted opening may be formed by squeezing the inner end of the tube 2IA. It will be seen that no room is provided for the Wire either to buckle or to contact any substantial portion of the inner surface of the casing. Due to the arrangement of the slot, II2, the portion of the reel outside the slot, designated I03, surrounds all portions of the wire which have been wound upon the reel.

The lower ends of the slidable sections 22A, 23A are provided with enlarged extremities I22, I23, respectively,these parts also frictionally engaging the interiors of the tubes in which they are slidable to provide electrical contact between.

the sections. The upper ends of the outer sections are reduced in diameter, as shown in Fig. 2,-

so that the enlargements I22, I23 effectively pre-y vent escape of the inner sections from each other and from the outer section 2 IA.

When the reel is turned in a direction to wind the wire upon it, the sections are drawn downwardly into telescoping relation, the wire being fed into the slot I I2 from the inner end, and each succeeding turn wound on the reel forces those previously wound to slide longitudinally along the reel and into the slot.

The first turn is thus wound around the reel close to the shoulder III], while the next turn is wound in the same place, but forces the first turn into the slot during the continued winding. When the reel is turned in 'the opposite direction, the Wire is forced upwardly, to project the antenna. The tendency of the wire coiled upon the reel to unwind and expand during such unreeling can cause no binding of the reel in the casing by clutch action, since the turns cannot expand into contact with the interior of the casing itself, engaging only the guard portion I03, which turns as a part of the reel and assists in projecting the wire.

A screw I may extend through the side of the casing I00 and into the outer section 2IA of the aerial to assist in locking the aerial sections in place as well as to provide a lead-in connection, the wire I2'I being attached to the screw and extending to the radio apparatus (unshown).

As shown in Fig. 1, the aerial assembly may be mounted beneath the cowl IIA of the vehicle body IOA, while the antenna sections may extend through but be insulated from the cowling, the positioning and insulation being effected by means of insulating filler blocks A, A, shaped conformably to the cowl and m ths inclination of the aerial assembly, the parts being held by a nut 35A screwed onto a threaded sleeve I35 surrounding and secured to the fixed antenna section 2 IA. I

The Bowden wire I08 by which the reel is turned may extend through the instrument panel I6A, and a knob I30 may be attached to the wire to enable convenient operation of the reel,

I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and 1 claims rather than to the foregoing description to indicate the scope of the invention.

I claim: An extensible and retractible antenna construction comprising a; plurality of telescoping members, one slidable within another, a flexible but relatively incompressible filamentary element connected to an inner one of said members and also extending through and from the outer thereof, and means for actuating said element to pro- =ject andretract the inner member, comprising a casing having a substantially cylindrical chamber therein closed at one end by an end wall, a reel rotatable in the chamber and held against longitudinal movement therein, one face of said reel closely abutting and being closed by said end wall, the filamentary element being connected to the reel, said reel having a substantially cylindrical winding surface upon which said filamentary element may be wound to retract the antenna element and from which it may be unwound to project said antenna element, a guard portion rotatable with said reel and surrounding but spaced from said winding surface, the spacing between saidwinding surface and guard portion forming a slot opening laterally against said end wall of greater thickness than said filamentary element but less than twice the thickness thereof, and a guide opening extending through the casing at its closed end terminating at and substantially tangentially with respect to said winding surface, means at the open end'of the' slot for feeding the filamentary element laterally into and from the same when the reel is turned to wind and unwind said filamentary element, the winding surface and the inner surface of said guard portion being relatively smooth, whereby the turns of saidfilamentary element may slide laterally in and out of said slot as said element is wound and unwound, said reel and guard portion being integral, the winding surface being longer than the guard portion and projects beyond the open end of the slot, said means for feeding the filamentary element comprising an opening through said casing large enough to permit the filamentary element to pass freely therethrough but of insufiicient size to permit buckling of said element, said opening extending substantially tangentially with respect to said Winding surface and angularly inwardly toward said slot, to feed the filamentary element onto said winding surface and angularly inwardly toward the bottom of said slot as the reel is turned to 'wind the filamentary element thereupon, and vic versa. 7

EMIL CARLSON. 

